The thing I noticed about the symmetry is that all symmetrical number pairs add up to 9. In other words, every time you solve a 1, you solve an 8. Every 2 solves a 7, every 3 solves a 6, and every 4 solves a 5.
Interestingly, this is an additional symmetry on top of the already existing positional symmetry. The creator could have used any other symbols and it would have worked aswell, but he chose those because it would make the puzzle even more beautiful!
When I saw that all the complement numbers totalled to 9, and the central 3x3 has all the pairs opposite each other surrounding the 9, my brain melted. What a beautiful, satisfying puzzle!
@@bace1000 Same logic as what placed the 5 in the middle in ua-cam.com/video/f-o2RxvdZvw/v-deo.html. I'm surprised that Simon didn't remember this, he was quite excited about it at the time.
“Oh, it’s over” “Wait it’s been 20 minutes?” I don’t know why this was in the recommend but I just sat and watched someone play sudoku for 20 minutes but I swear it was more like 8
I don't even like sudoku. Not sure why this was recommended to me. But I watched it all and still gave a like just because of Simon's reaction and pure joyous wonder. Even if you don't like something yourself you can still see the beauty in something that someone else is truly passionate about.
Yeah, I tried solving it before I watched this video, and just seeing yourself solve it is simply amazing and to see him solve it afterwards, it is just an amazing experience.
It's not part of the rule set, but the solution wraps around the "consecutive" rule as well, in that no 1's and 9's are adjacent in the final solution either. More than that, the adjacent rule also wraps around the edges of the board as well. Even more than that, the knight's rule wraps around the edges too.
@@DanielVCOliveira Not the edge wrap-around, but the 1-9 wraparound is due to the symmetry where rotating around the center swaps 18 27 36 45. Thus 1 is never next to 9, for then there would be an 8 next to a 9 in the symmetric location.
Great observation that this pattern wraps around horizontally and vertically and also warps from 9 to 1. I'm new to advanced sudoku but I remember another "miracle sudoku" pattern from this channel which had the additional restriction of "anti-king's move". That rule set is so restrictive, there is really only one solution (with reflections, rotations and shifts but only one way, not the other). The rule set of this puzzle allows more solutions and requires you to do some actual sudoku.
As a physicist whose whole career centers around symmetries in nature, it was wonderful to see this symmetry blossom like a flower from such seemingly innocuous initial conditions.
My physic professor used to say "symmetry of the causes leads to symmetry of the consequences", and that's exactly what we see here: a symmetrical initial situation necessarily leads to a symmetrical resolution.
Here is what I guess: Each pair of symmetric numbers sums up to 9 (so 9 has to be on its own and therefore has to sit right in the middle). So if we rotate the entire sudoku 180 degrees and sum up all the corresponding digits we get all 9's except 18 in the middle. Also since 9 has its special role there's no need to give any 9's at the beginning. And for the 4 pairs 1-8 2-7 3-6 4-5, to minimize the initial clues the designer avoids giving the 1-8 pair due to the consecutive number rule. And for the initial positions, putting the numbers closer to the middle maximizes the power of the knight rule, hence minimizing the number of initial clues. Given the rigidity of the additional rules, I wonder if this is the only possible configuration under the new rules and only 8 initial clues (treating its reflections and rotations as the same).
@@vladako78 when your too accustomed to some things, other may be harder to see than for a begginer (even i've seen it before him and i did not resolve more than 100 sudoku in my life (maybe just passed the 100 mark but not by a lot)
@@vladako78 To be fair, there is a problem with this symetry which is not perfect, as someone else mentioned in a comment I read. If you pair n with 9-n, and leave 9 alone, then all goes well except for one thing: 8 and 9 cannot be adjacent, while 1 and 9 can. In this particular case, it works anyway, because you can add the rule "1 and 9 cannot be adjacent", and you still have an unique solution. But there is no garanty (or at least, not trivial to me) that would be always the case.
@@lucas29476 simon did a great video on it. do a search on the channel for "The Sudoku Technique The Computer Doesn't Know ." i believe it goes something like this: "in a sudoku with symmetrical given digits, if you can use logic to figure out any digit, then you can use the same logic to find the digit in the symmetrically opposite cell." basically "if you start with all symmetrical givens, you'll end up with a symmetrical solution."
There is no constraint that 9 cannot be adjacent to 1 so it's not symmetrical. If the constructor had used pairs adding to 10 and used 5 as the unpaired digit, it would them be symmetrical.
There is a very easy way to see why the symmetry of the given numbers must also yield a symmetry of the solution: If we assume there is a unique solution and that the rules of the game are also symmetric, i.e. if a state x of the game is allowed, than also the state Sx, where the symmetry acted on x, is allowed, suppose we got a solution y of the game. As a solution it would have to be allowed, but then since the rules are symmetric also Sy is an allowed solution, since it would still be based on the symmetric starting position. But as we assumed uniqueness of the solution, Sy=y, so y is symmetric.
Solved in 29:03. Amazing puzzle, very fun to solve. 17:14 the pair of 5's in the lower right also forces the 4 into the left box because a 4 cannot be next to a 5.
As a mathematician, this puzzle got me so excited the instant the “trick” was discovered (I’m still not sure how it ended up in my recommended videos though)!
Absolutely lovely puzzle. I noticed the potential for Gurth's symmetrical placement pretty early on, but assumed it wouldn't actually come up because the additional rules gave a way to break the symmetry later on, but it was cool to realize that even with all the extra restrictions it still worked. (Although I don't know if it _has_ to work, since a solution could put 1s next to 9s in order to make itself unique without breaking the initial symmetry.)
Why was this in my recommended? I don't know. Did I understand anything in this video? No. Did I enjoy it for no reason and watch the entire video? Yes.
@@DarkAngelEU he just make it seem easy, it is not (at least i know i would take AT LEAST 2* more time than him, maybe 3 or 4 time more) And an easy sudoku doesn't mean it can't be beautiful
An amazing puzzle. started moving too fast and I had to start over and slow myself down. You start out with a number of options to follow and that just grows. The 189 triple is all over the place. I had to take it slow with the symmetry, but it was amazing. It was too easy to get into the brilliance of the design, I found myself just staring at it. Marvelous puzzle type.
Not sure how YT got me here, but it did and I love it. I never did any Sudoku with rules beyond the standard ones. This was a work of beauty. I neer thought I'd enjoy watching Sudoku solving THIS much. Great vid, instant sub. Rishi, please create more of this!
Don’t know if anyone has mentioned this but for all rows barring the third from the right and third from the left every other number going vertically in the row counts up to nine. Every other number. The last row for instance starts at the bottom with 9, skip, 1, skip, 2, skip, 3, skip, 4... the patterning here is so much deeper than we realize
No one : Absolutely no one UA-cam recommendation : Here's this guy solving impossible Soduku grids Me : I was not looking for this but this was amazing.
21:34 and what a video that is, making me watch someone resolve a sudoku while talking like a noble during 22 min, and enjoying it, seriously what a video that is
14:28 Looking at the upper left block, you can determine where a few numbers go by looking at the 4/5 options. So if a 4 is in row 1, a 5 can't be in column 1 because of the adjacent rule so it must be in column 3. If the 4 is in row 2, the 5 can't go there anymore so the 5 must be in column 3. So we can see that the 5 must be in column 3 which gives you the 5 and the 3 for that block.
Oh boy, this devil took me 48 minutes. That was quite the ride. First time trying unconventional sudoku and i am not disappointed. Thank you for a great puzzle!
Column 1,2, 5,7,9 all have number with the similar sequence, that is: 948,372,615. This help to make the knight move condition and symmetry of the puzzle.
I loved watching him solve this one, purely because it was the first one I’ve watched where I saw the pattern of symmetry and figured out a lot of things before he did!
19:30 you put a 1 or 9 in the top right box middle square, but that's next to an 8, so it can't be a 9, so you could have immediately called it a 1. This is the one bit of logic that I noticed CAN'T be done symmetrically in the opposite corner when I solved the puzzle, because the non-consecutive rule doesn't consider the digits as being in a loop (as far as I know, the rules allow a 9 adjacent to a 1, even though it never occurs in the solution!). Even though there are other ways to solve it so you don't need to make that move, I found that fascinating.
It took me an hour in hand. Last time I did one his puzzles it took me the same time as him, but this one was annoying, I get forgetting to apply the no-consecutive rule and get stuck.
What a treat. Took me 28 minutes, spotted the symmetry later than Simon, but was too "afraid" to blindly follow the symmetry, but once it was spotted it was easy to apply the logic at the other end, really great puzzle indeed!
Tried this puzzle myself before watching (took me 2 hours, most of which was spent scratching my head) and holy mother of god, the symmetry about the center point of the puzzle with the way the numbers are paired together actually brought a smile to my face. This puzzle is absolutely incredible.
42 minutes, but dang that was a fun puzzle! I want more like it. Now that I watched your solve... guess I went about it all wrong in rippling out from the centre placing all possibilities for each cell and whittling it down from there. So, I had a grid of mostly all 189 and numbers after a while before it all tumbled down from a 7. Some neat collisions of boxes where I had overlapping doubles with consecutive digits meaning they had to be the opposite ends... but bout it for neatness. I sort of saw the symmetry, but not like you did... and I think that also contributed to the slow factor.
I stumbled upon this quite randomly due to UA-cam's wild algorithm, but I'm not mad at all. I used to be fascinated with Sudoku puzzles when I was younger, and watching you get excited over such an expertly built puzzle has inspired me to get into Sudoku a little more. It's a seemingly simple puzzle game that has more layers to it than many could ever guess. I love it.
Absolutely gorgeous. Solving this was more fun than any other puzzle I had done so far, and watching you do it (much quicker of course) afterwards was so wonderful. The puzzle is a stunning work of art, and your reaction to it was really fun - even if I caught myself pointing and internally shouting "No, you can rule out that number there, look at what's consecutive/in knight's move!!!" at some points :D I really love anti knight sudokus, they are SO fun and I find them very intuitive!
You know, when I try some of the harder puzzles and sometimes get stuck, give up and come back to the video, I usually say "What is this sorcery?". Quite fitting for this one.
Not played sudoku for a long time, watched the video and wanted to try, took around 1 hour, never tried with restrictions other than the normal ones, very enjoyable, thank you.
The symmetry is great, but my favorite part was that you have to place virtually all of the 2,3,4,5,6,7's to be able to place a single 1,8, or 9. It seems intentional to surround the 2's/7's with 3-6's to not give away any information about 1 or 8 until you have to.
When you look at the initial numbers, you can see that they all add up to nine when you take there circular symmetrical. 2 with 7, 3 with 6 and 4 with 5. This means that whenever you find a logic on a side of the board, you can find the same logic on the other side. By construction, the entire board will be symmetrical. One side with normal series, one to nine, and one part with 9-x. The only number which paired with himself being Nine himself.
one can determine the digit at r2c1 in a different way (@17:48): If it would be a 5, the only place for the 4 is r1c1; This violates the condition that orthogonal digits can't have a difference of 1. Thus, r2c1 is a 4.
I thought it too but didn't dare fill it in quite yet :P. Thought it'd sort itself out anyway without cracking my head trying to confirm my logic on that one :P.
Around the 8:30 mark, when Simon says "there's something going on here" I noticed that the mirror effect was between pairs adding to 9 (2 and 7, 3 and 6, 4 and 5). At that time, all those pairs were filled on the central 3x3 square, leaving out the 1,8 and 9 - meaning there was a remaining pair adding to 9 (1 and 8). Considering those 3 numbers were to be filled in a diagonal, and that all the other pairs were in opposite sides of each other, through logic you could argue the 1 and 8 would also go on opposite sides of each other, leaving the middle square to be 9. The correct result verifies this, which is pretty amazing! It is indeed a beautiful puzzle, with the 9 in the centre of it all and the rest of the grid filled with symmetrical [adding to 9] pairs.
Wow, this puzzle is absolutely gorgeous. Absolute top marks for Rishi on this one, it was stunningly great to play. Initially I couldn't possibly see how to get into this puzzle, but suddenly things started to click in place in my head, and I found myself completely sucked in. Absolutely amazing logic, and brilliant setting all around. One of my favorites for sure! Final time, 18:22.
Thank you for the appreciation. If you are interested, you can try out other puzzles on my blog. They are free for all to download and try. rishipuri.blogspot.com or if you wish to solve online, then you can play a classic sudoku and a variant every day on my website sudokumaniacs.com . It's absolutely free :)
The inputs were almost symmetric so the result must be. The only non-symmetric part was distance to "edge" (extremes 1 and 9). In fact there is no 1 near 9 in the result despite not being forbidden because 9 is symmetric to itself and it can't be close to 8 so it can't be close to 1 either. Also because of the symmetry 9 could be put in the center almost immediately (assuming unique solution)
I did solve the 3 middle rows first and yes 891 would be the middle just due to how that orthogonal rule functions. And if you look at the 9s you'll clearly see that they are symmetrical and I do think Rishi Puri created this puzzle backwards because if you look at it from a symmetrical point of view it's perfectly symmetrical.1-8 2-7 3-6 4-5 as pairs. So if you knew a 1 position you automatically know an 8 position. That's the real trick to this puzzle.
Wow. Easily one of the best puzzles I've had the pleasure of completing. I didn't even go for speed because there were too many moments where I just slowed down to appreciate the puzzle setter's brilliance.
I believe UA-cam puts high priority on educational/sciencey type videos. So a lot of science, math, and quirky puzzles get thrown around in the side bar.
This was the first one I solved in about half an hour!! I'm so proud of me! I also did not come back to Simon's hints after the initial break in until I solved it. Thank you Simon, you made me fall in love with sudokus and I am getting better and better thanks to your videos! Now, time to watch how Simon did it and learn more!
For puzzles like these, I use the following logic : “if there was a non-symmetrical solution, then the puzzle would be ambiguious, as reversing the solution would yield another valid solution. Hence, all solutions must keep the same symmetry as the starting point.
If the final solution had been asymmetric and contained an adjacent 1 and 9, "reversing" the solution would give an adjacent 8 and 9, which is not allowed
whoever made this didn't meant to make this puzzle hard, but to make it fun, what a genius the knight's move and the adjacent rules are seriously fascinating
@@Davedave000 You can not win at tic tac toe. You can just have an opponent who does a mistake. To quote from the movie war games: "The only winning move is not to play": ua-cam.com/video/F7qOV8xonfY/v-deo.html
Anyone else spotted that bit of logic where by you could have ruled out the 4/5 in the top left and bottom right 3×3 ? The 4 could have never been in row 8 column 9 as that would have forced a 5 in row 9 column 9 14:18. Similarly the 5 could be ruled out in row 2 column 1
Brilliant puzzle solving. I've dabbled in Sudoku, but just watching this video, I learned so much about the different deductions and strategies used in solving one of these. Simon's enthusiasm for the puzzle was contagious, I found myself surprised at how much joy I was getting just watching him discover the symmetry and elegance of the puzzle. One thing he didn't specifically point out was that the symmetry was based on sums of 9. I'd imagine he worked that out by the end, but it just bears noting that all of the "matched" pairs added up to 9 (4 with 5, 2 with 7, etc) or 18 (in the case of 9 with 9 itself). Thanks for an enjoyable video.
I'm a recent subscriber, found it just before the miracle sudoku video blew up and have been just going many of your old videos. I just worked this one in 38:33 as a result of noticing the beautiful symmetry. Such a piece of majesty and the first of the sudokus I've gotten without bifurcation or needing to wait for some of your logic to crack the solve.
Anyone have a link to more of those type? I really like the non-consecutive orthogonal adjacent + no knights move duplicate rule combinations but I'm doubting a lot of these puzzles exist.
One great thing about puzzles with initial symmetries, and symmetric rules, is that there must be a symmetric solution. There may be others, but we usually assume there is a unique solution. This makes solving these kinds of puzzles quite easy.
I don't remember ever searching for "sudoku" in UA-cam, but I really enjoyed this recommended video. I rewinded so many times to understand all the steps.
Got there eventually, but it took me 37 minutes because I didn't spot nearly so many symmetries as you. A great example of why I usually go ahead and watch your solve after. Wonderful puzzle.
it took me roughly an hour, I loved the symmetry because that helped me know when I found certain parts that I would find something similar with the other numbers. I honestly didn't try to get 1, 8, or 9 until I had most of the other numbers figured out. Once I solved them, I solved the 189 it in the upper left section first, I stopped checking the knights movement stuff as I already had checked that for most of the numbers. I loved it
Hey Simon! I actually managed this puzzle on my own before watching you solve it and I fell in love with the symmetry in it. Took me a bit longer than you but I had a lot of fun with this one. This is one of my all time favorite sudoku puzzles and I'm so glad you brought it to my attention.
this puzzle felt SO good to do, it took me almost 39 minutes and i enjoyed every second. this was so satisfying and entertaining, i think it'd be a great entry into sudoku variants for anyone because it was very doable but still felt like you were unwinding some kind of amazing contraption
Hello, love your new app. But I enjoy the sandwich one a little bit more. I was wondering if you can make a video about how to create a Sudoku. It is not necessary to have a fancy puzzle as an example. I'm just interested in the Prozess itself. That would be wonderful. Thx for all the content you provide.
Took me an hour, but well worth the time! I now understand why Simon loves these so much, the feeling of figuring it out and actually solving it is amazing!
I stopped playing sudoku a while ago because normal apps get boring after a while. But when this video got recommended to me I decided to give this puzzle a try and finished it in an hour twenty. It was fun! Thanks for this opportunity, I'll try seeking out more fun puzzles.
This one was amazing! I gave up on it first time, then came back to it today and the symmetry unwinding the whole puzzle feels SO satisfying! Best part? I went about it in a whirlwind/tornado pattern, completely differently than you - and still the symmetry worked in the same amazing way. So many ways to do this. This sudoku is a work of art! It was most fun I had with a puzzle in a while~ Thank you so much for featuring this one! Now onto the other wizard one. :3
As soon asthe symmetry began to manifest, i referred back to the wheel of 8 givens surrounding the center 3x3 and noticed certain features that I felt confident ensured this initial symmetry would persist in depth. In fact I was SO confident of this that I immediately placed a 9 in the center square simply because what I had noticed made it pretty unlikely that anything other than 9 would dare occupy the exact center of this puzzle! For anyone curious to know what i spotted, my verbose account here follows: I noticed that 9 was the sum of each of the symmetry's paired givens, and of the absent digits, I was sure 9 would be the only unpaired digit with 8 and 1 making the symmetry final dance partners. We start with the pair closest in value, (4,5) using them twice each to plug in the wheel's corners, so to speak. Then #s in the pair next closest in value, (3,6) separate the corner digits that are also closest in value - namely the repeated digits - so 3, the lower of the separators, divides the 5s, the greater of the repeats. Similarly, the higher separator, 6 comes between the lower repeats, the 4s. Using the same approach, the most disparate givens couple (2,7) will separate the corners most disparate as well, namely between the 4 and 5. Then I thought, "Of course there'd be no 8 or 1 given" and that's when I entered that 9!
can someone explain to me at 5:50 how he came to the conclusion "so that must be 2" ? I am a sudoku beginner and would love some pro advise...thanks i advance ^^
There are 3 squares in the center, each of which can only be 1, 8, or 9. So there is one of each, we just don't know in what order. So that square which we knew to be 1, 2, or 9 cannot be 1 or 9 since we know 1 & 9 are already represented in one of those three squares.
i've watched like 20 of your vids at least, and this is the first one I did before watching. It may have took me 1h3m23s, but it was very enjoyable. It is the first non-classic sudoku I've ever done. you gave me appreciation for the symmetry, and your strategies from previous knight sudoku videos came in handy. I also picked up your 3 games bundle on steam. I look forward to testing my prior classic skills and implementing the techniques that you've taught me. Thanks for getting me hooked, and introducing me to what it means for a sudoku to be beautiful.
29:05 Once i got the key insight that if a number is locked to one of two adjacent positions, a consecutive number is locked out of both, the rest of the puzzle fell quite easily. Really fun!
I used that same logic a few times. I'm a bit surprised that Simon didn't (not that he needed it). I also reasoned that when I saw 2s locked into r1 and r3 in c5, that r2c5 can't be a 1 or 3.
Sudoku is a powerful thing. In the span of 10 minutes I went from nearly having a stroke trying to understand the rules of this puzzle, to screaming at my screen; "YOU KNOW WHERE THE 2 IS, THE KNIGHTS STEP THE KNIGHTS STEEEEEP" I haven't played Sudoku in a solid decade, but quality video, did enjoy
Find yourself someone who talks about you like Simon talks about symmetry in Sudoku puzzles
This is Simon not Mark
Mark the Bowman's bingo & Simon the logician
@@j0hnc00 Whoops, thanks, edited
And still he doesn’t understand all of it... he could put the nine in the center in the moment he noticed that it was the only one without symmetrical
I would give this a like, but I don't want to mess up your number of likes.
The thing I noticed about the symmetry is that all symmetrical number pairs add up to 9. In other words, every time you solve a 1, you solve an 8. Every 2 solves a 7, every 3 solves a 6, and every 4 solves a 5.
This is amazing!
Interestingly, this is an additional symmetry on top of the already existing positional symmetry. The creator could have used any other symbols and it would have worked aswell, but he chose those because it would make the puzzle even more beautiful!
@@nikolasscholz7983 Even crazier... The 1rst, 4th, 6th, and 9th columns are the same order of numbers, and so are the 2nd and 8th.
Except 9s, which pair with other 9s
@@patrickhector they add to a multiple of 9 (9+9=18) so you can say the all add to a multiple of 9
When I saw that all the complement numbers totalled to 9, and the central 3x3 has all the pairs opposite each other surrounding the 9, my brain melted. What a beautiful, satisfying puzzle!
bruh
Placing the 9 in the center can be done at the very start of the puzzle,if you realize it's the only number without a symmetric pair
@@bace1000 Same logic as what placed the 5 in the middle in ua-cam.com/video/f-o2RxvdZvw/v-deo.html. I'm surprised that Simon didn't remember this, he was quite excited about it at the time.
A thing I didn't notice when solving it myself and only noticed after finishing it: the consecutive number rule is cyclical. That's also pretty nice.
Not just the central 3x3, the whole puzzle. If you flip the puzzle diagonally you get an 'opposite' number, and the 9's are completely symmetrical.
“Oh, it’s over” “Wait it’s been 20 minutes?”
I don’t know why this was in the recommend but I just sat and watched someone play sudoku for 20 minutes but I swear it was more like 8
When he finished the puzzle I was sure he was going to start a second because there was no way it had been 20 minutes.
But if it was 8 then next to it can't be a 7 or 9... Wait, what did I just watch???
same here buddy, I thought I'd watch for like 5 mins lol
Exactly my reaction! His wholesome, geeky admiration of the puzzle was contagious. As soon as he began to notice a pattern, I was hooked.
Yes Yes Yes Yes, YES!
How is this the best let’s play I’ve seen
Drunken Knight first sub comment on this top comment
It’s Simon’s sense of wonder and discovery that makes it so good. You can just hear the amazement in his voice. It never gets old.
@@GunganWorks thank you for answering my joke; i may sleep easy tonight, now getting it 🤙✊✌️
I don't even like sudoku. Not sure why this was recommended to me. But I watched it all and still gave a like just because of Simon's reaction and pure joyous wonder. Even if you don't like something yourself you can still see the beauty in something that someone else is truly passionate about.
You and me buddy you and me
Holy moly!
Yep. Same for me too(except I kinda like sudoku a little)
can I like this comment a thousand times over? x3
Dahmer was passionate too.
That’s not a puzzle, that’s a piece of art
Yeah, I tried solving it before I watched this video, and just seeing yourself solve it is simply amazing and to see him solve it afterwards, it is just an amazing experience.
It's not part of the rule set, but the solution wraps around the "consecutive" rule as well, in that no 1's and 9's are adjacent in the final solution either.
More than that, the adjacent rule also wraps around the edges of the board as well.
Even more than that, the knight's rule wraps around the edges too.
Is this intentional or just a by-product of the rules?
@@DanielVCOliveira Not the edge wrap-around, but the 1-9 wraparound is due to the symmetry where rotating around the center swaps 18 27 36 45. Thus 1 is never next to 9, for then there would be an 8 next to a 9 in the symmetric location.
+
Great observation that this pattern wraps around horizontally and vertically and also warps from 9 to 1. I'm new to advanced sudoku but I remember another "miracle sudoku" pattern from this channel which had the additional restriction of "anti-king's move". That rule set is so restrictive, there is really only one solution (with reflections, rotations and shifts but only one way, not the other). The rule set of this puzzle allows more solutions and requires you to do some actual sudoku.
As a physicist whose whole career centers around symmetries in nature, it was wonderful to see this symmetry blossom like a flower from such seemingly innocuous initial conditions.
My physic professor used to say "symmetry of the causes leads to symmetry of the consequences", and that's exactly what we see here: a symmetrical initial situation necessarily leads to a symmetrical resolution.
"initial conditions"
Flashbacks to PDE course intensify
Y'all talking about physics and my dumbass who in cc just like mmm me like puzzles
I like flowers
@@MoiMagnus1er Until you get to spontaneous symmetry breaking, which is cool and weird.
Here is what I guess:
Each pair of symmetric numbers sums up to 9 (so 9 has to be on its own and therefore has to sit right in the middle).
So if we rotate the entire sudoku 180 degrees and sum up all the corresponding digits we get all 9's except 18 in the middle.
Also since 9 has its special role there's no need to give any 9's at the beginning.
And for the 4 pairs 1-8 2-7 3-6 4-5, to minimize the initial clues the designer avoids giving the 1-8 pair due to the consecutive number rule.
And for the initial positions, putting the numbers closer to the middle maximizes the power of the knight rule, hence minimizing the number of initial clues.
Given the rigidity of the additional rules, I wonder if this is the only possible configuration under the new rules and only 8 initial clues (treating its reflections and rotations as the same).
When you figured out that 1 and 8 were paired I said that forces 9 in the center center... and it did.
Yes, I was surprised too. How can you be so expert in puzzles and not see such clear symmetry right away? Would have saved him a whole lot of effort
@@vladako78 when your too accustomed to some things, other may be harder to see than for a begginer (even i've seen it before him and i did not resolve more than 100 sudoku in my life (maybe just passed the 100 mark but not by a lot)
Not even into puzzles, but intuition said 9 was in the middle really early on in the pairing realisation.
@@vladako78 To be fair, there is a problem with this symetry which is not perfect, as someone else mentioned in a comment I read. If you pair n with 9-n, and leave 9 alone, then all goes well except for one thing: 8 and 9 cannot be adjacent, while 1 and 9 can.
In this particular case, it works anyway, because you can add the rule "1 and 9 cannot be adjacent", and you still have an unique solution. But there is no garanty (or at least, not trivial to me) that would be always the case.
Got the same feeling with the center 9. It just felt like that in an instant.
And Gurth’s symmetrical displacement is hiding in this puzzle, even with so few digits!
Because I spent 60 minutes on the last Gurth puzzle Simon posted, I spotted it here around 7 minutes!
Do you mind explaining what is this symmetrical displacement?
@@lucas29476 simon did a great video on it. do a search on the channel for "The Sudoku Technique The Computer Doesn't Know
." i believe it goes something like this: "in a sudoku with symmetrical given digits, if you can use logic to figure out any digit, then you can use the same logic to find the digit in the symmetrically opposite cell." basically "if you start with all symmetrical givens, you'll end up with a symmetrical solution."
There is no constraint that 9 cannot be adjacent to 1 so it's not symmetrical. If the constructor had used pairs adding to 10 and used 5 as the unpaired digit, it would them be symmetrical.
There is a very easy way to see why the symmetry of the given numbers must also yield a symmetry of the solution:
If we assume there is a unique solution and that the rules of the game are also symmetric, i.e. if a state x of the game is allowed, than also the state Sx, where the symmetry acted on x, is allowed, suppose we got a solution y of the game. As a solution it would have to be allowed, but then since the rules are symmetric also Sy is an allowed solution, since it would still be based on the symmetric starting position. But as we assumed uniqueness of the solution, Sy=y, so y is symmetric.
Solved in 29:03. Amazing puzzle, very fun to solve. 17:14 the pair of 5's in the lower right also forces the 4 into the left box because a 4 cannot be next to a 5.
Took me 2 hours, but solved it. This was one of the most satisfying sudokus I've ever seen.
Same for me :)
Same here x)
As a mathematician, this puzzle got me so excited the instant the “trick” was discovered (I’m still not sure how it ended up in my recommended videos though)!
actually a not bad watch, unsure how i got here tho #youtube algorithm
yep
dude same here, suddenly this was in my feed. and im not even mad i watched this. this was amazing
Well it was one of those, Its late i should go to sle.. Oh this looks interesting. But you know it was interesting
That moment when you realise that UA-cam algorithm know what you like more than yourself
i know right
I'd never done a sudoku with rules beyond the standard set... this one took me an hour XD
same
same. made a mistake somewhere and had to remake about a quarter of the puzzle. (crosschecked with the video haha)
Absolutely lovely puzzle. I noticed the potential for Gurth's symmetrical placement pretty early on, but assumed it wouldn't actually come up because the additional rules gave a way to break the symmetry later on, but it was cool to realize that even with all the extra restrictions it still worked. (Although I don't know if it _has_ to work, since a solution could put 1s next to 9s in order to make itself unique without breaking the initial symmetry.)
Why was this in my recommended? I don't know.
Did I understand anything in this video? No.
Did I enjoy it for no reason and watch the entire video? Yes.
The machine revolution is already on baby, hell yeah!
I'm tickled at how tickled Simon gets by the symmetry of this puzzle.
I have no clue what he's excited about but im happy for him anyway
This sodoku is matemathicaly structured on so many levels it's astonishing. it's like a mandala.
Me neither. It's such an easy solution.
@@DarkAngelEU he just make it seem easy, it is not (at least i know i would take AT LEAST 2* more time than him, maybe 3 or 4 time more)
And an easy sudoku doesn't mean it can't be beautiful
yeyoistheking it also doesn’t mean it can be beautiful
Com-e Kem.p and yet it is
An amazing puzzle. started moving too fast and I had to start over and slow myself down. You start out with a number of options to follow and that just grows. The 189 triple is all over the place. I had to take it slow with the symmetry, but it was amazing. It was too easy to get into the brilliance of the design, I found myself just staring at it. Marvelous puzzle type.
I'm not sure why this was in my recommended but I'm glad it was.
Not sure how YT got me here, but it did and I love it. I never did any Sudoku with rules beyond the standard ones.
This was a work of beauty. I neer thought I'd enjoy watching Sudoku solving THIS much. Great vid, instant sub.
Rishi, please create more of this!
Don’t know if anyone has mentioned this but for all rows barring the third from the right and third from the left every other number going vertically in the row counts up to nine. Every other number. The last row for instance starts at the bottom with 9, skip, 1, skip, 2, skip, 3, skip, 4... the patterning here is so much deeper than we realize
in between those is 5,6,7,8,9....
:)
yes! i noticed that near the middle of the video. he would say "this could be a 1,8 or a 9 and already knew what number it would be.
162738495
That’s insane
No one :
Absolutely no one
UA-cam recommendation : Here's this guy solving impossible Soduku grids
Me : I was not looking for this but this was amazing.
Same
21:34 and what a video that is, making me watch someone resolve a sudoku while talking like a noble during 22 min, and enjoying it, seriously what a video that is
14:28 Looking at the upper left block, you can determine where a few numbers go by looking at the 4/5 options. So if a 4 is in row 1, a 5 can't be in column 1 because of the adjacent rule so it must be in column 3. If the 4 is in row 2, the 5 can't go there anymore so the 5 must be in column 3. So we can see that the 5 must be in column 3 which gives you the 5 and the 3 for that block.
Oh boy, this devil took me 48 minutes. That was quite the ride. First time trying unconventional sudoku and i am not disappointed. Thank you for a great puzzle!
Column 1,2, 5,7,9 all have number with the similar sequence, that is: 948,372,615. This help to make the knight move condition and symmetry of the puzzle.
I loved watching him solve this one, purely because it was the first one I’ve watched where I saw the pattern of symmetry and figured out a lot of things before he did!
19:30 you put a 1 or 9 in the top right box middle square, but that's next to an 8, so it can't be a 9, so you could have immediately called it a 1. This is the one bit of logic that I noticed CAN'T be done symmetrically in the opposite corner when I solved the puzzle, because the non-consecutive rule doesn't consider the digits as being in a loop (as far as I know, the rules allow a 9 adjacent to a 1, even though it never occurs in the solution!). Even though there are other ways to solve it so you don't need to make that move, I found that fascinating.
It took me 1 and a half hours. And yet he resolve it in 10 minutes.
It took me an hour in hand. Last time I did one his puzzles it took me the same time as him, but this one was annoying, I get forgetting to apply the no-consecutive rule and get stuck.
Same! And the way to solve it was sooooo different.
And still I feel like he was a little bit too exited, for example at 19:59 he is entering 1,9 which is already resolved if you look to the left.
What a treat. Took me 28 minutes, spotted the symmetry later than Simon, but was too "afraid" to blindly follow the symmetry, but once it was spotted it was easy to apply the logic at the other end, really great puzzle indeed!
This may be the most beautiful and satisfying sudoku I've ever completed
Tried this puzzle myself before watching (took me 2 hours, most of which was spent scratching my head) and holy mother of god, the symmetry about the center point of the puzzle with the way the numbers are paired together actually brought a smile to my face. This puzzle is absolutely incredible.
42 minutes, but dang that was a fun puzzle! I want more like it.
Now that I watched your solve... guess I went about it all wrong in rippling out from the centre placing all possibilities for each cell and whittling it down from there. So, I had a grid of mostly all 189 and numbers after a while before it all tumbled down from a 7. Some neat collisions of boxes where I had overlapping doubles with consecutive digits meaning they had to be the opposite ends... but bout it for neatness. I sort of saw the symmetry, but not like you did... and I think that also contributed to the slow factor.
I stumbled upon this quite randomly due to UA-cam's wild algorithm, but I'm not mad at all. I used to be fascinated with Sudoku puzzles when I was younger, and watching you get excited over such an expertly built puzzle has inspired me to get into Sudoku a little more. It's a seemingly simple puzzle game that has more layers to it than many could ever guess. I love it.
welcome to another episode of why the heck is this in my recommended
and why the heck i watched it though to the end
and why the heck did i enjoy it that much
and why the heck I wanted more
Absolutely gorgeous. Solving this was more fun than any other puzzle I had done so far, and watching you do it (much quicker of course) afterwards was so wonderful. The puzzle is a stunning work of art, and your reaction to it was really fun - even if I caught myself pointing and internally shouting "No, you can rule out that number there, look at what's consecutive/in knight's move!!!" at some points :D I really love anti knight sudokus, they are SO fun and I find them very intuitive!
You know, when I try some of the harder puzzles and sometimes get stuck, give up and come back to the video, I usually say "What is this sorcery?". Quite fitting for this one.
Not played sudoku for a long time, watched the video and wanted to try, took around 1 hour, never tried with restrictions other than the normal ones, very enjoyable, thank you.
The symmetry is great, but my favorite part was that you have to place virtually all of the 2,3,4,5,6,7's to be able to place a single 1,8, or 9. It seems intentional to surround the 2's/7's with 3-6's to not give away any information about 1 or 8 until you have to.
When you look at the initial numbers, you can see that they all add up to nine when you take there circular symmetrical. 2 with 7, 3 with 6 and 4 with 5. This means that whenever you find a logic on a side of the board, you can find the same logic on the other side. By construction, the entire board will be symmetrical. One side with normal series, one to nine, and one part with 9-x. The only number which paired with himself being Nine himself.
the 9 are even symetical with eachother when looking diagonally mind blown
And rotationally symmetrical when you look at the 4 other slots.
one can determine the digit at r2c1 in a different way (@17:48):
If it would be a 5, the only place for the 4 is r1c1; This violates the condition that orthogonal digits can't have a difference of 1.
Thus, r2c1 is a 4.
the moment i spotted the symetry i knew center would be a 9.
me to if 1 and 8 are pairs then 9 needs to be in the center
I thought it too but didn't dare fill it in quite yet :P. Thought it'd sort itself out anyway without cracking my head trying to confirm my logic on that one :P.
Around the 8:30 mark, when Simon says "there's something going on here" I noticed that the mirror effect was between pairs adding to 9 (2 and 7, 3 and 6, 4 and 5). At that time, all those pairs were filled on the central 3x3 square, leaving out the 1,8 and 9 - meaning there was a remaining pair adding to 9 (1 and 8). Considering those 3 numbers were to be filled in a diagonal, and that all the other pairs were in opposite sides of each other, through logic you could argue the 1 and 8 would also go on opposite sides of each other, leaving the middle square to be 9. The correct result verifies this, which is pretty amazing! It is indeed a beautiful puzzle, with the 9 in the centre of it all and the rest of the grid filled with symmetrical [adding to 9] pairs.
That was one of the absolutely funniest, and at the same time, actually quite easily understandable solve I've seen on the channel
Wow, this puzzle is absolutely gorgeous. Absolute top marks for Rishi on this one, it was stunningly great to play. Initially I couldn't possibly see how to get into this puzzle, but suddenly things started to click in place in my head, and I found myself completely sucked in. Absolutely amazing logic, and brilliant setting all around. One of my favorites for sure! Final time, 18:22.
Thank you for the appreciation. If you are interested, you can try out other puzzles on my blog. They are free for all to download and try. rishipuri.blogspot.com or if you wish to solve online, then you can play a classic sudoku and a variant every day on my website sudokumaniacs.com . It's absolutely free :)
The inputs were almost symmetric so the result must be. The only non-symmetric part was distance to "edge" (extremes 1 and 9). In fact there is no 1 near 9 in the result despite not being forbidden because 9 is symmetric to itself and it can't be close to 8 so it can't be close to 1 either.
Also because of the symmetry 9 could be put in the center almost immediately (assuming unique solution)
I did solve the 3 middle rows first and yes 891 would be the middle just due to how that orthogonal rule functions.
And if you look at the 9s you'll clearly see that they are symmetrical and I do think Rishi Puri created this puzzle backwards because if you look at it from a symmetrical point of view it's perfectly symmetrical.1-8 2-7 3-6 4-5 as pairs. So if you knew a 1 position you automatically know an 8 position. That's the real trick to this puzzle.
Wow. Easily one of the best puzzles I've had the pleasure of completing. I didn't even go for speed because there were too many moments where I just slowed down to appreciate the puzzle setter's brilliance.
Thank you for the appreciation.
How did this get in my recommended.
nice profile pic that song is great
You don't remember watching that puzzle video from 8 years ago? The algorithm recommends videos of things you've watched in the past----
I believe UA-cam puts high priority on educational/sciencey type videos. So a lot of science, math, and quirky puzzles get thrown around in the side bar.
this video got in my recommended after listening to lone digger lol
The fact that you left a comment makes me think that the UA-cam algorithm is doing a good job now.
This was the first one I solved in about half an hour!! I'm so proud of me! I also did not come back to Simon's hints after the initial break in until I solved it. Thank you Simon, you made me fall in love with sudokus and I am getting better and better thanks to your videos! Now, time to watch how Simon did it and learn more!
For puzzles like these, I use the following logic : “if there was a non-symmetrical solution, then the puzzle would be ambiguious, as reversing the solution would yield another valid solution. Hence, all solutions must keep the same symmetry as the starting point.
If the final solution had been asymmetric and contained an adjacent 1 and 9, "reversing" the solution would give an adjacent 8 and 9, which is not allowed
whoever made this didn't meant to make this puzzle hard, but to make it fun, what a genius
the knight's move and the adjacent rules are seriously fascinating
Thank you :)
And I thought I was cool winning a game of Tic Tac Toe.
Technically, winning a game of Tic Tac Toe would be more impressive as two equally skilled players will always stalemate against each other.
@@Davedave000 You can not win at tic tac toe. You can just have an opponent who does a mistake. To quote from the movie war games: "The only winning move is not to play":
ua-cam.com/video/F7qOV8xonfY/v-deo.html
@@Bunny99s That's what winning is called yes.
Anyone else spotted that bit of logic where by you could have ruled out the 4/5 in the top left and bottom right 3×3 ? The 4 could have never been in row 8 column 9 as that would have forced a 5 in row 9 column 9 14:18. Similarly the 5 could be ruled out in row 2 column 1
That is exactly how I placed a 4 in R8 C7.
you can use gurth's symmetrical placement for this piece of art.
Brilliant puzzle solving. I've dabbled in Sudoku, but just watching this video, I learned so much about the different deductions and strategies used in solving one of these. Simon's enthusiasm for the puzzle was contagious, I found myself surprised at how much joy I was getting just watching him discover the symmetry and elegance of the puzzle.
One thing he didn't specifically point out was that the symmetry was based on sums of 9. I'd imagine he worked that out by the end, but it just bears noting that all of the "matched" pairs added up to 9 (4 with 5, 2 with 7, etc) or 18 (in the case of 9 with 9 itself).
Thanks for an enjoyable video.
This the kinda stuff you stumble upon at 3am and then decide to sleep 😂
I'm a recent subscriber, found it just before the miracle sudoku video blew up and have been just going many of your old videos. I just worked this one in 38:33 as a result of noticing the beautiful symmetry. Such a piece of majesty and the first of the sudokus I've gotten without bifurcation or needing to wait for some of your logic to crack the solve.
Anyone have a link to more of those type? I really like the non-consecutive orthogonal adjacent + no knights move duplicate rule combinations but I'm doubting a lot of these puzzles exist.
One great thing about puzzles with initial symmetries, and symmetric rules, is that there must be a symmetric solution. There may be others, but we usually assume there is a unique solution. This makes solving these kinds of puzzles quite easy.
I've never before seen anyone get so excited about symmetry :-)
Never met a physicist ?
I don't remember ever searching for "sudoku" in UA-cam, but I really enjoyed this recommended video. I rewinded so many times to understand all the steps.
This is such a beautiful design. I loved solving it.
Got there eventually, but it took me 37 minutes because I didn't spot nearly so many symmetries as you. A great example of why I usually go ahead and watch your solve after. Wonderful puzzle.
It took me an hour and a half but actually managed to finish this one! Much frustration until I found the 189 trio :0
it took me roughly an hour, I loved the symmetry because that helped me know when I found certain parts that I would find something similar with the other numbers. I honestly didn't try to get 1, 8, or 9 until I had most of the other numbers figured out. Once I solved them, I solved the 189 it in the upper left section first, I stopped checking the knights movement stuff as I already had checked that for most of the numbers. I loved it
Hey Simon! I actually managed this puzzle on my own before watching you solve it and I fell in love with the symmetry in it. Took me a bit longer than you but I had a lot of fun with this one. This is one of my all time favorite sudoku puzzles and I'm so glad you brought it to my attention.
this one is insane, everything is symmetrical, I love it
this puzzle felt SO good to do, it took me almost 39 minutes and i enjoyed every second. this was so satisfying and entertaining, i think it'd be a great entry into sudoku variants for anyone because it was very doable but still felt like you were unwinding some kind of amazing contraption
Hello, love your new app. But I enjoy the sandwich one a little bit more.
I was wondering if you can make a video about how to create a Sudoku. It is not necessary to have a fancy puzzle as an example. I'm just interested in the Prozess itself. That would be wonderful. Thx for all the content you provide.
They made one a few months ago: ua-cam.com/video/936S5jWQTYE/v-deo.html
@@AnRuixuan awesome. Thank you so much. I should have Googled first :D
What the app.
Took me an hour, but well worth the time! I now understand why Simon loves these so much, the feeling of figuring it out and actually solving it is amazing!
Me: hahaha what a nerd
Also me: *watches the whole video* huh...neat
I just watched someone play Sudoku, and was MESMERIZED. Seeing so many other people equally hooked astounds me.
29:04 on this time.
I really liked this puzzle. some very cool deductions needed to be made to get it to the breaking point
I stopped playing sudoku a while ago because normal apps get boring after a while. But when this video got recommended to me I decided to give this puzzle a try and finished it in an hour twenty. It was fun! Thanks for this opportunity, I'll try seeking out more fun puzzles.
I don't think I've ever felt vicarious giddiness before.
This one was amazing! I gave up on it first time, then came back to it today and the symmetry unwinding the whole puzzle feels SO satisfying! Best part? I went about it in a whirlwind/tornado pattern, completely differently than you - and still the symmetry worked in the same amazing way. So many ways to do this. This sudoku is a work of art! It was most fun I had with a puzzle in a while~
Thank you so much for featuring this one!
Now onto the other wizard one. :3
I wonder if you replace each number by a colour, then a surprising art will appear
Kinda curious now lol.
I think it's a nice extra, that the two numbers, who mirror each other in the puzzle, always add up to 9 and the 9 kind of mirrors itself.
This is one of the most wholesome things I’ve seen.
The symmetry is a rotational symmetry of 180° where rotating means switching 45, 36, 27,18 and leaving all the 9's. Beautiful!
"I have absolutely no clue how to solve this problem"
Me too. Jesus, my brain
He said he had no clue how to create this puzzle. He had no problem solving it in the video.
So this, like for many others, popped into my recommendations randomly. The pure joy and wonder made this video fly by. An oddly compelling watch.
"If you play Sudoku on your phone, your a gamer!"
Very happy with 28 mins to solve. Picked up the 189 triplets early and repeatedly. Loved this puzzle!
I was like just before he found the 1 and 8. Every pair symmetrical counterpart adds to 9 so 1 and 8 are counterparts and 9 in the middle
I've never even watched a sudoku video before but somehow youtube recommended me this. Couldn't be happier with the result, awesome video, subscribed.
Me seeing Simon miss out on the same simple knight’s move logic I did: I guess I did alright with the solve
As soon asthe symmetry began to manifest, i referred back to the wheel of 8 givens surrounding the center 3x3 and noticed certain features that I felt confident ensured this initial symmetry would persist in depth. In fact I was SO confident of this that I immediately placed a 9 in the center square simply because what I had noticed made it pretty unlikely that anything other than 9 would dare occupy the exact center of this puzzle! For anyone curious to know what i spotted, my verbose account here follows:
I noticed that 9 was the sum of each of the symmetry's paired givens, and of the absent digits, I was sure 9 would be the only unpaired digit with 8 and 1 making the symmetry final dance partners. We start with the pair closest in value, (4,5) using them twice each to plug in the wheel's corners, so to speak. Then #s in the pair next closest in value, (3,6) separate the corner digits that are also closest in value - namely the repeated digits - so 3, the lower of the separators, divides the 5s, the greater of the repeats. Similarly, the higher separator, 6 comes between the lower repeats, the 4s. Using the same approach, the most disparate givens couple (2,7) will separate the corners most disparate as well, namely between the 4 and 5. Then I thought, "Of course there'd be no 8 or 1 given" and that's when I entered that 9!
UA-cam recommendations really going in an odd direction...
That wsa one of the most incredible puzzles I've ever done. Thanks for sharing!
can someone explain to me at 5:50 how he came to the conclusion "so that must be 2" ? I am a sudoku beginner and would love some pro advise...thanks i advance ^^
There are 3 squares in the center, each of which can only be 1, 8, or 9. So there is one of each, we just don't know in what order. So that square which we knew to be 1, 2, or 9 cannot be 1 or 9 since we know 1 & 9 are already represented in one of those three squares.
@@kitcarmstrong hmm yeah i got it now ... i just watched it again and then it made sense :) thanks for explaining ^^
i've watched like 20 of your vids at least, and this is the first one I did before watching. It may have took me 1h3m23s, but it was very enjoyable. It is the first non-classic sudoku I've ever done. you gave me appreciation for the symmetry, and your strategies from previous knight sudoku videos came in handy. I also picked up your 3 games bundle on steam. I look forward to testing my prior classic skills and implementing the techniques that you've taught me. Thanks for getting me hooked, and introducing me to what it means for a sudoku to be beautiful.
You're a wizard, Harry
Came to post it but here's your like
robxDin sammie200345
Ron is a much better chess player, and both he and Hermione are better at logic puzzles.
and a thumpin goodin I'd wager, once you've been trained up a bit.
29:05 Once i got the key insight that if a number is locked to one of two adjacent positions, a consecutive number is locked out of both, the rest of the puzzle fell quite easily. Really fun!
I used that same logic a few times. I'm a bit surprised that Simon didn't (not that he needed it). I also reasoned that when I saw 2s locked into r1 and r3 in c5, that r2c5 can't be a 1 or 3.
11:52 He forget the Knight Rule of that 7
Sudoku is a powerful thing. In the span of 10 minutes I went from nearly having a stroke trying to understand the rules of this puzzle, to screaming at my screen; "YOU KNOW WHERE THE 2 IS, THE KNIGHTS STEP THE KNIGHTS STEEEEEP"
I haven't played Sudoku in a solid decade, but quality video, did enjoy